Spark-arrester.



0. N. TERRY. sum: ARBESTER. APPLIOATIOH FILED APR. 7, 1908.

Patented Dec. 8, 190 8.

UNITED srrnrrns PATENT OFFICE.

OTIS N. TERRY, OF LINCOLN, NEBRASKA, ASSIGNOR OF ONE-HALF TO ROBERT D.SMITH,

OF BOSTON, MASSAGH USETTS.

SPABK-ARRESTER.

Specification of Letters Patent.

Patented Dec. s, 1908.

To all whom it may concern:

Be it known that I, OTIS N. TERRY, a citizen of the United States,residing at Lincoln, in the county of Lancaster and State of Nebrask'a,have invented certain new and useful Improvements in Spark-Arresters, ofwhich the following is a specification.

The object of my invention is to provide a new and improved device forpreventing the escape of sparks or live cinders from the smoke stack ofa locomotive. My invention is also capable of employment in otherconnections.

The invention may be advantageously employed Within a so-called diamondhead smoke stack.

The object and nature of the invention will appear more fully from thefollowing specification and claims taken in connectionwith theaccompanying drawings in which Figure 1 is a vertical sectionof adiamond head smoke stack showin my improvements. Fig. 2 is a plan view0? the netting which extends across the top of the smoke stack. Fig. 3is a vertical section of said netting,

- and Fig. 4 is a cross section on an enlarged scale of one of the gratebars shown in Fig. 1.

The ordinary cylindrical-smoke stack is designated by the referencenumeral 15. A little below the top edge'18 a flaring wall 16 is attachedwhich is continued above convergently in the wall 17. This smoke stackhead comprised of the oblique walls 16 and 17 is what is commonly knownas a diamond head. Near the upper edge of the cylindrical smoke stackwall 15 the brackets19 are attached by means of the bolts 20. At theirupper ends these brackets support two parallel grates 21 and 22,which-are spaced a art by means of washers 24, being clampe tightlyagainst these washers by means of the nuts 23 and 25.

Each bar- 26 of the lower grate 21 is thicker on the upper side than onthe lower side; this the spaces 27 between consecutive bars convergeupwardly. The upperface of each bar has a channel 28. In the particularembodiment of my invention which I have chosen to illustrate anddescribe, the two grates are castings made from the same mold and theupper grate 22 is the same. as the lower grate. inverted. This will beat once apparent from an inspection of Fig.1. Thus the bars 29 of theupper grate are narrower on the upper surface, the spaces 30 between theconsecutive barsdiverge upwardly, and

the channels 31 are on the lower faces of the ate are stag-- gered withrespect to those of t e lower grate, that is,each bar 29 is opposite aspace 27.

This relation may be more exactly defined as follows: Each when adiameter is drawn across the grate bars the center of the grate will lieon this diameter midway between the center ofone of the bars on one sideand the center of the adjacent space between bars on the other side.This condition being satisfied, when one of the grates is reversed andlaid on top of the other, the bars of one directly over the spaces of te other grate, and vice versa.

A wire netting 32 is stretched across the top of the diamond head smokestack,as shown in Fig. 1, the edges being clamped in place by means ofthe rings 33 and 33*. Short pieces of wire 34 are bent around thestrands of wire netting 32, the ends being brought together so as toprevent their escape, yet permitting them to hang loosely from thenetting.

The operation of my invention will be readily understood by thoseskilled in the art. The escaping gases will be directed up through thelower grate 21 and will impinge against the channels 31 in the lowerfaces of the uppergrate bar, thus sparks and hve cinders will beinterrupted and in some cases crushed by the impact and will either fallback down the smoke stack or be blown on out with decreased velocitythrough the upper spaces 30. The wire netting 32 efl'ectually preventsthe escape of any sparks or live cinders that may e large enough to dodamage. As is well-known, such a wire netting as ordinarily designed issomewhat likely to become clogged with soot and cinders.- I havefound byactual experience that this clogging is prevented by having loosemembers comprised in the netting. These loose members may be of variousdesigns. In the particular embodiment ofmy invention which I have chosento illustrate and describe, I have'simply taken ordinary fence wirestaples and looped them over the strands of the netting pinching theends together to prevent their escape. However, it is obvious thatvarious other forms of loose members mi ht beemployed. These loosemembers by t eir vibration prevent the accumulation of soot andcinderson the netate is so constructed that ate will come tin It is to beobserved that the grates arranged across the stack and provided with orthe netting may, if desired, be employed separately, or theircombination is very effective for the desired purpose.

Considerable.difliculty has been experienced in securing an effectivespark arrester that will keep clean when used with lignite coal, and Ibelieve that my invention is a solution of the diflicultyr I claim: I

1. In combination, a diamond head smokestack, and a perforated screenacross the opening therefrom, said screen having a plurality of memberseach loosely attached thereto, and supported thereby.

2. In combination, a smoke conduit and a spark arresting devicecomprising a perforated screen arranged across the conduit with aplurality of members each loosely attached to the screen, and supportedthereby.

3. In combination, a smoke-stack and a spark arrester comprising aperforated screen arranged across the stack and provided with aplurality of depending members loosely engaging the screen, andsupported thereby. Y

4. In combination, a smoke stack and a spark arrester comprising a Wirenetting short lengths of wire bent about the strands and hanging looselytherefrom.

5. In 'combination, a smoke-stack and a spark arrester comprising a.square mesh wire netting arranged across the stack and provided withordinary fence wirestaples hooked over the strands and dependingtherefrom and having their ends bent together.

6. In combination, a diamond head smokestack, a perforated screen acrosssaid smokestack, members loosely attached to the screen, and a pluralityof grates extending across the smoke-stack below the screen.

7. In combination, a smoke-stack, a perforated screen across said stack,depending members loosely engaging the screen, and a pair of gratesextending across the smokestack below the screen, the bars of saidgrates being staggered.

In testimony whereof, I have subscribed \Vit nesses i LiLLLiN A. KIBBY,ANNIE C. COURTENAY.

